Polyurethane Foam Material Research Articles

Ameliorating the comprehensive performance of rigid polyurethane foam insulating materials by green cork for building energy conservation

Biomass-modified polyurethane (PU) foam materials are vital to promote the sustainable development, but the balance between their mechanical strength and thermal insulating ability remains a challenge compared to the petrochemical-based PU foams. Herein, an appropriate amount of cork is introduced to fabricate PU composite foams with good thermal insulating performance and mechanical strength. The added cork could act as a nucleating agent during the foaming process, further tailor the foam structure and enhance their comprehensive performance. The optimal composite foams containing the peak cork usage of 24 % also belong to the high-efficiency insulating materials, with a thermal conductivity of 0.043 W m−1 K−1, a tensile strength of 0.17 MPa, a bending strength of 0.16 MPa, and good impact resistance. This research provides valuable insights for developing the comprehensive PU insulating materials by utilizing eco-friendly cork as substitutes, and offers a reference for highly efficient utilization of biomass resources.

Extending the Natural Neighbour Radial Point Interpolation Meshless Method to the Multiscale Analysis of Sandwich Beams with Polyurethane Foam Core

This work investigates the mechanical behaviour of sandwich beams with cellular cores using a multiscale approach combined with a meshless method, the Natural Neighbour Radial Point Interpolation Method (NNRPIM). The analysis is divided into two steps, aiming to analyse the efficiency of NNRPIM formulation when combined with homogenisation techniques for a multiscale computational framework of large-scale sandwich beam problems. In the first step, the cellular core material undergoes a controlled modification process in which circular holes are introduced into bulk polyurethane foam (PUF) to create materials with varying volume fractions. Subsequently, a homogenisation technique is combined with NNRPIM to determine the homogenised mechanical properties of these PUF materials with different porosities. In this step, NNRPIM solutions are compared with high-order FEM simulations. While the results demonstrate that RPIM can approximate high-order FEM solutions, it is observed that the computational cost increases significantly when aiming for comparable smoothness in the approximations. The second step applies the homogenised mechanical properties obtained in the first step to analyse large-scale sandwich beam problems with both homogeneous and functionally graded cores. The results reveal the capability of NNRPIM to closely replicate the solutions obtained from FEM analyses. Furthermore, an analysis of stress distributions along the beam thickness highlights a tendency for some NNRPIM formulations to yield slightly lower stress values near the domain boundaries. However, convergence towards agreement among different formulations is observed with mesh refinement. The findings of this study show that NNRPIM can be used as an alternative numerical method to FEM for analysing sandwich structures.

Uncertainty and sensitivity analysis of non-acoustic parameters on acoustic characteristics prediction models for porous foam materials

Porous foam materials are widely used in noise control applications. Their acoustic performance can be predicted by acoustic models composed of non-acoustic parameters such as flow resistivity, porosity, tortuosity, viscosity, and characteristic length. However, the influence of these parameters on model outputs varies across different frequency ranges. Therefore, when using a single model for predictions across the entire frequency range, parameters may not fully act within the frequency range where their influence is greatest. To reduce prediction errors and improve the correlation between predicted numerical results and experimental data, uncertainty and sensitivity analyses can be conducted to determine the extent of each parameter's influence at different frequency ranges. In this study, polyurethane foam materials are investigated, and uncertainty and sensitivity analyses are performed on two acoustic models. Firstly, the uncertainty of parameters is assessed using the Monte Carlo method. Secondly, Sobol index method is employed to reveal the influence of parameters across various frequency ranges. Finally, by comparing the results of both analyses, the optimal frequency ranges for each parameter can be summarized. This provides valuable reference for enhancing the accuracy of acoustic model predictions.

Research on Polyurethane Creep Prediction Model Based on BWO-BP

Abstract Polyurethane foam materials can creep under the influence of temperature, humidity, and pressure during use, which seriously affects their safety and state of use. Therefore, studying the creep behavior of polyurethane foam materials and developing corresponding creep mechanism models have significant scientific value for understanding their damage patterns. As a type of machine learning, Backpropagation (BP) neural network can be used for data analysis. However, there are many issues when determining the network structure. Whale Optimization (BWO) algorithm, as a type of swarm intelligence algorithm, can efficiently determine the framework of the BP model. BP which has been optimized through the BWO algorithm, has been utilized to construct a model for the prediction of polyurethane’s creep failure. The optimization process has significantly lowered the mean squared error from 0.30 in the non-optimized BP model to 0.07 in the enhanced BWO-BP model, which validates the effectiveness of the proposed algorithm.

Multiscale Analysis of Sandwich Beams with Polyurethane Foam Core: A Comparative Study of Finite Element Methods and Radial Point Interpolation Method.

This study presents a comprehensive multiscale analysis of sandwich beams with a polyurethane foam (PUF) core, delivering a numerical comparison between finite element methods (FEMs) and a meshless method: the radial point interpolation method (RPIM). This work aims to combine RPIM with homogenisation techniques for multiscale analysis, being divided in two phases. In the first phase, bulk PUF material was modified by incorporating circular holes to create PUFs with varying volume fractions. Then, using a homogenisation technique coupled with FEM and four versions of RPIM, the homogenised mechanical properties of distinct PUF with different volume fractions were determined. It was observed that RPIM formulations, with higher-order integration schemes, are capable of approximating the solution and field smoothness of high-order FEM formulations. However, seeking a comparable field smoothness represents prohibitive computational costs for RPIM formulations. In a second phase, the obtained homogenised mechanical properties were applied to large-scale sandwich beam problems with homogeneous and approximately functionally graded cores, showing RPIM's capability to closely approximate FEM results. The analysis of stress distributions along the thickness of the beam highlighted RPIM's tendency to yield lower stress values near domain edges, albeit with convergence towards agreement among different formulations. It was found that RPIM formulations with lower nodal connectivity are very efficient, balancing computational cost and accuracy. Overall, this study shows RPIM's viability as an alternative to FEM for addressing practical elasticity applications.

Experimental analysis of thermal energy efficient clay brick incorporated with phase change material and insulation

In this study, a combination of thermal capacitance (Phase Change Material) and thermal resistance (Polyurethane Foam and air) materials are incorporated into Energy Efficient Clay Brick (EECB) to assess its indoor thermal performance. Various configurations of EECBs were developed, featuring two rectangular slots to accommodate PCM, Polyurethane Foam (PUF), and air in varying orders. These EECBs were then tested in a real outdoor tropical climate over three consecutive days to evaluate the impact of integrating PCM, PUF, and air in indoor thermal performance. The results indicate that the combination of PCM and PUF in EECB-5, with PCM on the outer side and PUF on the inner side, demonstrates the best indoor thermal behavior compared to other configurations. EECB-5 exhibits a maximum reduction in indoor peak temperature of 11.2 % and a time lag ranging from 130 to 140 minutes. EECB-5 shows a decrement factor of 0.54, followed by 0.55 for EECB-2. Additionally, EECB-5 configuration achieves an average surface temperature reduction of 15.01 % compared to Conventional Brick (CB). In addition, the simulation analysis of various configurations of bricks further confirms that the EECB-5 configuration exhibits superior indoor temperature regulation compared to other configurations. It is concluded that PCM enhances the thermal capacitance of building elements by increasing their latent heat storage capacity. Hence, Phase Change Material (PCM) into building elements can help to provide viable solutions for creating energy-efficient building envelopes.

Study on Fast Liquefaction and Characterization of Produced Polyurethane Foam Materials from Moso Bamboo.

Although bamboo is widely distributed in Japan, its applications are very limited due to its poor combustion efficiency for fuel. In recent years, the expansion of abandoned bamboo forests has become a social issue. In this research, the possibility of a liquefaction process with fast and efficient liquefaction conditions using moso bamboo as raw material was examined. Adding 20 wt% ethylene carbonates to the conventional polyethylene glycol/glycerol mixed solvent system, the liquefaction time was successfully shortened from 120 to 60 min. At the same time, the amount of sulfuric acid used as a catalyst was reduced from 3 wt% to 2 wt%. Furthermore, polyurethane foam was prepared from the liquefied product under these conditions, and its physical properties were evaluated. In addition, the filler effects of rice husk biochar and moso bamboo fine meals for the polyurethane foams were characterized by using scanning electron microscopy (SEM) and thermogravimetry and differential thermal analysis (TG-DTA), and the water absorption and physical density were measured. As a result, the water absorption rate of bamboo fine meal-added foam and the thermal stability of rice husk biochar-added foam were improved. These results suggested that moso bamboo meals were made more hydrophilic, and the carbon content of rice husk biochar was increased.

Determinants of Temperature Development during Dental Implant Surgery

Mechanical and thermal trauma during implant surgery may be reasons for initial peri-implant bone loss. Temperature development during drilling and implant insertion were quantified in this series of in vitro and animal experiments. Polyurethane foam material mimicking different classes of alveolar bone was used as a model material for simulating implant surgery. Using thermocouples, temperature development was determined in the model material at depths of 3 mm and 10 mm during site preparation and implant insertion. Additionally, an infrared camera allowed for measuring drill temperatures both in vitro and as part of an animal trial using an intraoral minipig model. Drill diameter and repeated usage of drills did not have a major effect on temperature generation. The addition of a diamond-like carbon coating, bone density, predrilling, and irrigation heavily affected intraosseous temperatures. In vivo, applying regular drill protocols, an intraosseous temperature rise of approximately 3 °K was determined. Implant geometry as well as the amount of undersizing of an osteotomy governed heat generation during implant insertion. Drill protocols and the amount of undersizing of an implant osteotomy constitute parameters by which clinicians can limit trauma during implant surgery.

Preparation and energy absorption of flexible polyurethane foam with hollow glass microsphere

This paper presents the preparation of a partially open-cell and partially closed-cell flexible polyurethane foam material (flex-PUF), which exhibits improved cushioning performance compared to conventional protective materials. Hollow Glass Microspheres (HGM) were used as a filling material to enhance the compressibility of the material. In order to investigate the effects of HGM on the multi-impact protection and vibration damping performance of flex-PUF with different thicknesses, flex-PUF samples filled with varying volume fractions of HGM were subjected to multi-impact testing and dynamic viscoelasticity experiments. The destructive mechanism of HGM under impact was observed using scanning electron microscopy (SEM). The experimental results revealed that, under the same impact energy conditions, filling flex-PUF with HGM reduced the maximum impact displacement while enhancing energy absorption, although at the expense of cushioning performance. As the number of impact increases, the stiffness of flex-PUF decreased. In the vibration experiments, as the frequency increased, the proportion of flex-PUF’s viscous damping energy dissipation decreases.

Cushioning Performance of a Novel Polyurethane Foam Material Applied in Fragile Packaging

Cushioning Performance of a Novel Polyurethane Foam Material Applied in Fragile Packaging

An innovative approach for the passive cooling of batteries: An empirical investigation of copper deposition on polyurethane foam for the enhancement of phase change material

A proof-of-concept utilising Copper-Plated Polyurethane Foam (CPPF) and Phase Change Material (PCM) for passive thermal management of lithium-ion batteries is demonstrated in this study. The aim of this research is to assess the effectiveness of CPPF when utilised as a constituent substance in PCM/Foam composites. Six distinct configurations of PCM/Foam composites are presented in this work using 10-pore-per-inch foam. A total of four deposition foam samples were produced. Of these, three were created by gradually increasing the immersion time in an electroless copper plating solution. For the fourth sample, an electroless plating technique was utilised for 80 min, followed by an electroplating procedure to deposit an additional layer of copper. The evaluation entails examining each plated sample in comparison to a copper foam that is commercially available with a purity level of 99.99 %. The findings reveal that the electroless-plated specimens exhibit improved effectiveness after being subjected to a prolonged plating period of 80 min. The electroplated sample exhibited the greatest degree of effectiveness, as evidenced by a 64.4 % reduction in battery cell surface temperature(10.98 °C), which is almost identical to the 64.5 % decrease in temperature (11.03 °C) observed with commercial foam but coupled with 88.1 % decrease in mass. The results suggest that the CPPF-PCM composites offer effective passive cooling properties for batteries.

Thermal insulation properties of materials for fishing vessel coolboxes

Abstract Effective insulation is critical for traditional fishing boats because it helps to maintain the quality of the fish catch. Inadequate insulation can lead to significant economic losses for fishermen, as they may have to discard or sell the fish at a lower price. This study aimed to compare the thermal conductivity properties of three different insulation materials: Petung bamboo, polystyrene foam, and polyurethane foam. The experiment involved testing the density of the materials and conducting thermal conductivity tests. The results indicated that polyurethane foam is the best material for insulation because it has the lowest thermal conductivity value compared to laminated bamboo and polystyrene foam. The addition of more isocyanate mass fraction to the polyurethane foam material can increase its density and strength. This is because increasing the isocyanate concentration increases the cross-linking density of the foam, making it more durable and resilient. Moreover, higher density polyurethane foams exhibit lower heat conductivity, indicating better insulation qualities. This study highlights the importance of effective insulation to maintain the quality of the fish catch. The findings suggest that polyurethane foam, particularly with increased isocyanate concentration, is the most suitable material for insulation due to its superior insulation qualities.

Novel hybrid tube consists of GFRP-PU-graphite powder for lightweight structure applications

This research successfully introduced an innovative lightweight tube made from lightweight PU Foam material and reinforced with glass fiber. The key findings from the tests are as follows: Glass fiber-reinforced polymer (GFRP) tubes without polyurethane (PU) foam withstood a pressure of 4.03 kN in compression testing. The specimen with 5 % graphite filler had the highest density at 0.262 g/mm3, while the specimen with 10 % graphite filler had the lowest density. The specimen with 5 % graphite filler also exhibited the highest hardness (19.5 Shore Hardness D), whereas the specimen with 20 % graphite filler had the lowest hardness (13.2 Shore Hardness D). The contraction of PU foam significantly influenced the material strength. GFRP tubes reinforced with PU foam offer advantages in terms of material lightness and improved material strength. These tubes can be applied in structural, automotive, and aerospace applications.

Finite element modeling of the electrical impedance tomography technique driven by machine learning

To create a human-like skin for a robotic application, current touch sensor technologies have a few drawbacks. Electrical Impedance Tomography (EIT) is a candidate for this application due to its applicability over complex geometries; nevertheless, it has accuracy concerns. This study employs artificial neural networks (ANNs) to investigate the accuracy and capability of EIT-based touch sensors. A finite element (FE) model is utilized to solve the forward EIT problem while simultaneously determining the system’s comprehensive mechanical response. The FE model is comprised of a polyurethane (PU) foam domain, a conductive spray layer and a set of sixteen electrodes. To replicate the process of touching the sensor body, a punch of varying diameters and touch forces is utilized. The mechanical response of the sensor body is modeled using the hyperfoam material model calibrated through experimental uniaxial and shear test data, while the electric conductivity of the sprayed skin surface is obtained experimentally as function of applied strain. The viscoelastic behavior of the PU foam material is also obtained experimentally. These experimental data were implemented in the FE model through user subroutines to model the mechanical and electrical properties of the sensor in the EIT forward problem. The traditional EIT inverse problem image reconstruction was replaced utilizing ANNs as an alternative to extract mechanics based parameters. The ANNs were created to predict the spatial coordinates of the touch point, and they were proven to be extremely accurate. Using the EIT voltage readings as input, the ANNs were utilized to forecast the system’s mechanical behavior such as contact pressure, contact area, indentation depth, and touching force.

Bringing free weight areas under acoustic control

Fitness studios that are housed in office, residential, or hotel buildings are repeatedly confronted with the problem that the strong vibrations caused by dropping weights lead to noise and vibrations in the entire building or even cause damage to existing ceiling structures. For these situations, Getzner has developed the g-fit Shock Absorb system with low construction heights and low weight. This is achieved through several layers of polyurethane foam materials including high damping or high elasticity sub-layer. The impact is isolated, the drop energy is absorbed by the material and dangerous rebound of the weights (dumbbell, barbell, kettlebells, etc.) is prevented. But the best flooring system can hardly be used without a proper prognosis of the isolation effect and the achieved sound pressure level in adjacent rooms. This paper is about the development of a prognosis tool that allows to predict the sound pressure level as a function of the impact energy, the type of weight at gym, and the ceiling mass for all g-fit Shock Absorb floor coverings. The extensive drop tests as well as the evaluation and the development of a prediction function is described in detail and explained by examples.

Porous Thermal Insulation Polyurethane Foam Materials.

Porous thermal insulation materials (PTIMs) are a class of materials characterized by low thermal conductivity, low bulk density and high porosity. The low thermal conductivity of the gas enclosed in their pores allows them to achieve efficient thermal insulation, and are they among the most widely used and effective materials in thermal insulation material systems. Among the PTIMs, polyurethane foam (PUF) stands out as particularly promising. Its appeal comes from its multiple beneficial features, such as low density, low thermal conductivity and superior mechanical properties. Such attributes have propelled its broad application across domains encompassing construction, heterogeneous chemical equipment, water conservation and hydropower, and the aviation and aerospace fields. First, this article outlines the structure and properties of porous thermal insulation PUF materials. Next, it explores the methods of preparing porous thermal insulation PUF materials, evaluating the associated advantages and disadvantages of each technique. Following this, the mechanical properties, thermal conductivity, thermal stability, and flame-retardant characteristics of porous thermal insulation PUF materials are characterized. Lastly, the article provides insight into the prospective development trends pertaining to porous thermal insulation PUF materials.

Toxic Effects and Mechanisms of Polybrominated Diphenyl Ethers.

Polybrominated diphenyl ethers (PBDEs) are a group of flame retardants used in plastics, textiles, polyurethane foam, and other materials. They contain two halogenated aromatic rings bonded by an ester bond and are classified according to the number and position of bromine atoms. Due to their widespread use, PBDEs have been detected in soil, air, water, dust, and animal tissues. Besides, PBDEs have been found in various tissues, including liver, kidney, adipose, brain, breast milk and plasma. The continued accumulation of PBDEs has raised concerns about their potential toxicity, including hepatotoxicity, kidney toxicity, gut toxicity, thyroid toxicity, embryotoxicity, reproductive toxicity, neurotoxicity, and immunotoxicity. Previous studies have suggested that there may be various mechanisms contributing to PBDEs toxicity. The present study aimed to outline PBDEs' toxic effects and mechanisms on different organ systems. Given PBDEs' bioaccumulation and adverse impacts on human health and other living organisms, we summarize PBDEs' effects and potential toxicity mechanisms and tend to broaden the horizons to facilitate the design of new prevention strategies for PBDEs-induced toxicity.

Performances of green velvet material (PLON) used in upholstered furniture

Green Velvet Material (PLON), which is prepared from polyester slices, has been called a green material based on its ester composition, its ability to be degraded, and the possibility of recovering the value of used material by reprocessing. PLON is expected to be used as a material for the padding layer of upholstered furniture. This paper presented a comparative study of traditional flexible polyurethane foam and Green Velvet Material as the upholstered furniture’s padding layer. The compression mechanical properties of Green Velvet Material and flexible polyurethane foam, such as indentation force deflection, support performance, compression set, and resilience property, were analyzed. The results showed that Green Velvet Material had lower surface hardness and higher comfort compared to flexible polyurethane foam. In terms of resilience, both high-density and low-density Green Velvet Material performed better than the foam control group, but Green Velvet Material had a poorer ability to regain its shape after prolonged pressure. The 30 kg/m3 density Green Velvet Material was the closest to the compression and resilience properties of flexible polyurethane foam. The conclusions provide theoretical data for the effective and reasonable application of Green Velvet Material in upholstered furniture.

Analysis of Fire Simulation on Polyurethane Foam Using FDS in a University Meeting Room

The polyurethane foam material is commonly used and marketed in two forms, namely flexible and rigid. Flexible foam is used as a cushion, with various applications for commercial products such as chair support. Therefore, this study aims to describe the occurrence of a fire situation in a university room filled with many polyurethane foam chairs. It also aims to provide awareness regarding potential flame hazards, by using a fire modelling method with FDS. The results showed that fires on PU foam materials produced a high HRR and a wide spread of flame and smoke. From this context, the harmful effects of the fire on the room occupants were emphasized. The results obtained are expected to support the theory of compartment fire, flame distribution in solid materials, PU Foam inferno behaviour, etc. It is also expected to provide additional fire protection and evacuation training for room occupants.

Studies on Compressive Loading-characteristics of PU Foam Materials Used in Footwear for Obese

Optimum-designed footwear with polyurethane (PU) material for comfort is an important requirement for obese. Investigations on compressive behavior of varied designed footwear using 120 D PU material have been carried out. The energy absorption primarily depends on heel height, slope angle and load applied or body mass index of obese. Statistical analysis has been used to formulate the prediction of absorbed energy wherein a heel height of 30 mm with 20-degree angle provides optimum value with the incorporation of 120 D PU material. A coefficientof- determination (R2) value of 0.9406 confirms the suitability of the statistical regression model. Hence, the optimally designed footwear for higher energy absorption with 120 D PU foam material is recommendable for obese.